<?php

/*
 * This file is part of SwiftMailer. (c) 2004-2009 Chris Corbyn For the full copyright and license information, please view the LICENSE file that was distributed with this source code.
 */
require_once dirname ( __FILE__ ) . '/OutputByteStream.php';
require_once dirname ( __FILE__ ) . '/CharacterReaderFactory.php';

/**
 * An abstract means of reading and writing data in terms of characters as opposed
 * to bytes.
 * Classes implementing this interface may use a subsystem which requires less
 * memory than working with large strings of data.
 * 
 * @package Swift
 * @subpackage CharacterStream
 * @author Chris Corbyn
 */
interface Swift_CharacterStream {
	/**
	 * Set the character set used in this CharacterStream.
	 * 
	 * @param string $charset        	
	 */
	public function setCharacterSet($charset);
	
	/**
	 * Set the CharacterReaderFactory for multi charset support.
	 * 
	 * @param Swift_CharacterReaderFactory $factory        	
	 */
	public function setCharacterReaderFactory(Swift_CharacterReaderFactory $factory);
	
	/**
	 * Overwrite this character stream using the byte sequence in the byte stream.
	 * 
	 * @param Swift_OutputByteStream $os
	 *        	output stream to read from
	 */
	public function importByteStream(Swift_OutputByteStream $os);
	
	/**
	 * Import a string a bytes into this CharacterStream, overwriting any existing
	 * data in the stream.
	 * 
	 * @param string $string        	
	 */
	public function importString($string);
	
	/**
	 * Read $length characters from the stream and move the internal pointer
	 * $length further into the stream.
	 * 
	 * @param int $length        	
	 * @return string
	 */
	public function read($length);
	
	/**
	 * Read $length characters from the stream and return a 1-dimensional array
	 * containing there octet values.
	 * 
	 * @param int $length        	
	 * @return int[]
	 */
	public function readBytes($length);
	
	/**
	 * Write $chars to the end of the stream.
	 * 
	 * @param string $chars        	
	 */
	public function write($chars);
	
	/**
	 * Move the internal pointer to $charOffset in the stream.
	 * 
	 * @param int $charOffset        	
	 */
	public function setPointer($charOffset);
	
	/**
	 * Empty the stream and reset the internal pointer.
	 */
	public function flushContents();
}
